Fluid filter element

ABSTRACT

A filter element is removably positionable within a filter housing defining a filter chamber for said filter element. The filter housing comprises a standpipe extending within the filter chamber. The filter element includes a tubular filter media circumscribing the standpipe, a first end cap supporting the filter media at one end thereof, a second end cap longitudinally spaced from the first end cap and supporting the filter media at the opposite end thereof, and a center tube extending between the first and second end caps. The center tube has at least one inlet opening therethrough at a first end thereof adjacent to the first end cap and a standpipe opening therethrough at a second end thereof adjacent to the second end cap. The second end cap has at least one intake opening therethrough radially spaced from the standpipe opening in the center tube.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to fluid filter assemblies in general, and, moreparticularly, to a fluid filter assembly including a replaceable, fluidfilter element that actuates a flow control valve in a standpipe of afilter housing.

2. Description of the Prior Art

Many types of fuel filters are known in the prior art. A popular type offuel filter construction is one that has a housing which encloses areplaceable filter element. Fuel used to power a self-propelled vehicle,such as gasoline or diesel fuel, is cleansed of impurities as it passesthrough filter media of the filter element. The filter media capturesmany of the impurities that are removed from the fuel. Other impuritiescollect on the surface of the media and fall downward into a bottom areaof the filter housing from which they may be periodically removedthrough a drain valve.

Periodically the filter element must be replaced. Such periodicreplacement ensures that the filter element will not become so loadedwith impurities that fuel flow is restricted. Replacing the element alsoensures that impurities are removed from fuel before it is delivered toother fuel system components such as fuel injection pumps and fuelinjectors, where such contaminants may cause severe damage.

Changing filter elements may pose problems however. One common problemis that disturbance of the spent element during replacement may causecollected impurities to fall off the element. In some designs, theseimpurities may travel into the outlet of the filter housing. As a resultthese contaminants may reach the components downstream in the fuelsystem. Another problem with certain prior art fuel filter constructionsis that changing the element may require a mechanic to have skincontact-with the fuel. It is desirable to minimize such contact whenchanging a filter element.

While known liquid filters have proven to be acceptable for variousvehicular applications, such devices are nevertheless susceptible toimprovements that may enhance their performance and cost. With this inmind, a need exists to develop improved fluid filter assembly thatadvance the art.

SUMMARY OF THE INVENTION

The present invention provides a new and improved fluid filter assemblyproviding an inside-out flow pattern. Alternatively, the fluid filterassembly of the present invention may provide an outside-in flowpattern.

The fluid filter assembly in accordance with the present inventioncomprises a filter housing having a central axis and defining a filterchamber, a standpipe extending upwardly substantially coaxially to thecentral axis of the filter housing into the filter chamber so as todefine an internal flow passage, and a filter element removablypositionable within the filter chamber of the filter housing. The filterelement of the present invention comprises a tubular filter mediacircumscribing the central axis, a first end cap supporting the filtermedia at one end thereof, a second end cap longitudinally spaced fromthe first end cap and supporting the filter media at the opposite endthereof, and a center tube extending between the first and second endcaps.

The center tube is disposed about the standpipe substantially coaxiallywith the central axis so as to define an exit compartment between thecenter tube and the standpipe. The center tube has at least one inletopening therethrough at a first end thereof adjacent to the first endcap for providing fluid communication between said filter chamber andsaid exit compartment. The center tube further has a standpipe openingtherethrough at a second end thereof adjacent to the second end cap andthrough which the standpipe being inserted longitudinally into thecenter tube. In turn, the second end cap has at least one intake openingtherethrough radially spaced from the standpipe opening in the centertube for providing fluid communication between the filter chamber and avolume inside the filter element between the filter media and the centertube. Preferably, the center tube is homogenously formed integrally withthe second end cap as a single piece unitary member.

Accordance to the preferred embodiment of the present invention, thestandpipe is provided with a flow control valve for selectivelycontrolling fluid flow through the standpipe. The flow control valve isnormally in a closed position preventing flow through the internal flowpassage. The flow control valve is accessible from a distal end of thestandpipe and moveable into an open position allowing flow through theinternal flow passage.

Upon further study of the specification and appended claims, furtherfeatures and advantages of this invention will become apparent to thoseskilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent froma study of the following specification when viewed in light of theaccompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a fuel filter assembly in accordancewith the preferred embodiment of the present invention;

FIG. 2 is a cross-sectional view of a filter housing in accordance withthe preferred embodiment of the present invention;

FIG. 3 is a is a partially sectioned side view of a closure element of aflow control valve according to the exemplary embodiment of the presentinvention in an open position;

FIG. 4 is a bottom view of the closure element of the flow control valveaccording to the exemplary embodiment of the present invention in anopen position;

FIG. 5 is an exploded perspective view of a filter element in accordancewith the preferred embodiment of the present invention;

FIG. 6 is a perspective view of the filter element in accordance withthe preferred embodiment of the present invention;

FIG. 7 is a cross-sectional view of the filter element in accordancewith the preferred embodiment of the present invention;

FIG. 8 is a cross-sectional view of a first end cap of the filterelement in accordance with the preferred embodiment of the presentinvention formed integrally with a center tube;

FIG. 9 is a top view of the filter element in accordance with thepreferred embodiment of the present invention;

FIG. 10 is a bottom view of the filter element in accordance with thepreferred embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The preferred embodiment of the present invention will now be describedwith the reference to accompanying drawings. For purposes of thefollowing description, the terms “upper”, “lower”, “top”, “bottom”,“upward”, “downward”, “vertical”, “horizontal” and derivatives of suchterms shall relate to the invention as oriented in FIG. 1. However, itis to be understood that the invention may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventiveconcepts. Specific dimensions and other physical characteristicsrelating to the embodiments disclosed herein are not to be considered aslimiting, unless expressly stated otherwise.

FIG. 1 depicts a fluid filter assembly 10 in accordance with thepreferred embodiment of the present invention providing an inside-outflow pattern. It will be appreciated that in other embodiments of theinvention an outside-in flow pattern may be used. The fluid filterassembly 10 comprises a filter housing 12 and a replaceable (ordisposable) filter element 40 removably mounted within the filterhousing 12, the combination of which provides the filter assembly 10.Preferably, the filter assembly 10 is provided for filtering particulateimpurities from liquid fuels such as gasoline or diesel. It will beappreciated that the filter assembly 10 of the present invention may beused for filtering any appropriate fluid.

The filter housing 12, further illustrated in detail in FIG. 2, israther conventional and includes a cup-shaped bowl 14 having a centralaxis 16 and a opening at its top, and a cover 17 removably attached tothe bowl 14. Preferably, the cover 17 is threadedly attached to the bowl14. The filter housing 12 defines a filter chamber 15 into which thefilter element 40 is mounted.

The filter housing 12 is adapted to be connected to a fuel system of aninternal combustion engine (not shown) for receiving unfiltered fuel viaa fuel inlet port 18 and returning filtered fuel for combustion via afuel outlet port 20. Portion of the filtered fuel returns to a fuel tank(not shown) via a return port 22.

A standpipe 24 extends vertically upward substantially coaxially to thecentral axis 16 of the bowl 14. The standpipe 24 includes an internalflow passage 25 in fluid communication with the outlet port 20 and aflow control valve 26 adjacent to a distal end of the standpipe 24. Theflow control valve 26 is provided for opening and closing the filterchamber 15 of the filter housing 12 to the outlet port 20 depending uponwhether or not the filter element 40 has been properly mounted to thefilter housing 12. The standpipe 24 includes a cylindrical wall 27 whichhas a cylindrical interior surface adjacent its upper end. A pair ofradially extending port openings 32 extend through the wall 31 of thestandpipe 24.

The valve 26 includes a closure element 28 mounted for longitudinalmovement within the cylindrical wall 27 of the standpipe 24 and biasedby a spring 30 to a closed position for preventing fuel flow into thestandpipe 24 through the port openings 32. As illustrated in detail inFIGS. 3 and 4, the closure element 28 has a lower cylindrical portion 28a bounded by a cylindrical element wall 29 a, and a head portion 28 bwhich has a flat, solid, top portion 29 b. The closure element 28further includes cross members 31 that bound flow cavities 33. The crossmembers 31 extend through the element to top portion 29 b. The elementwall 29 a terminates at the head portion 29 b, however, and enablesfluid access to the flow cavities 33 between the cross members 31. Thecross members 31 also include cut-outs 31 a in the head portion 28 b tofacilitate fluid flow into the flow cavities 33.

The closure element 28 is sized so that the cylindrical wall 29 a andthe top portion 29 b are in close-fitting, movable relation with theinterior surface of the cylindrical wall 27 of the standpipe 24. Theclosure element 28 is thereby made longitudinally movable inside thecylindrical wall 27 of the standpipe 24. The spring 30 mounted in thestandpipe 24 serves as biasing means for biasing the closure element 28in the outward direction toward a top end 34 of the standpipe 24. Thestandpipe 24 has an annular shelf 24 a against which one end of the coilspring 30 bears, the other end of the coil spring bearing against thelower cylindrical portion 28 a of the closure element 28 to hold theflow control valve 26 in closed position.

The closure element 28, the standpipe 24 and the port openings 32therein operate together as the flow control valve 26 to control fluidcommunication between the filter chamber 15 inside the housing 12 andthe internal flow passage 25 of the standpipe 24. When the head portion28 b of the closure element 28 is adjacent the port openings 32 of thestandpipe 24 as shown in FIG. 1, the port openings 32, which enable thefluid to be admitted to the internal flow passage 25 of the standpipe24, are open. Fuel flows into the internal flow passage 25 of thestandpipe 24 and passes through flow cavities 33 in the closure element28, and eventually passes to the fuel outlet port 20 of the filterassembly 10. However, when the closure element 28 is disposed upwardfrom the position shown in FIG. 1 to the position shown in FIG. 2, thecylindrical portion 28 b of the closure element 28 is disposed with itscylindrical element wall 29 a adjacent and in blocking relation to theport openings 32. As a result, the fluid flow into the standpipe 24 isblocked.

The standpipe 24 also includes an actuator opening 36 at its top end 34for receiving an actuator pin of the filter element 40 that axiallydepresses the closure element 28 against the bias of the spring 30 toallow fuel flow through the port openings 32 past the closure element 28and to the fuel outlet port 20.

The replaceable filter element 40 is removably mounted in the filterchamber 15 of the filter housing 12. The filter element 40 illustratedin detail in FIGS. 3-6, includes a ring of a continuous, tubular filtermedia 42 in generally surrounding relation of the standpipe 24 so as tocircumscribe the central axis 16. The filter media 42 may be one ofseveral types of filter media material known in the art and adapted forremoving impurities from fluid that passes therethrough.

The filter element 40 further includes a first (upper) end cap 44 at itsupper end, and a second (lower) end cap 46 at its lower end. The endcaps 44 and 46 are engaging and supporting in fluid tight relation thering of filter media 42 at the opposite ends thereof in a conventionalmanner using potting compound or similar adhesive material. The filterelement 40 further includes a center tube 48 having a substantiallycylindrical side wall 49 extending vertically upward between the secondend cap 46 and the first end cap 44. As illustrated in FIG. 1, thecenter tube 48 is disposed about the standpipe 24 substantiallycoaxially to the central axis 16 so that the cylindrical side wall 49 ofthe center tube 48 is radially spaced from the standpipe 24 to form asubstantially cylindrical exit compartment 50 between the center tube 48and the standpipe 24. Preferably, the center tube 48 is homogenouslyformed integrally with the second end cap 46 as a single piece unitarymember. Alternatively, the center tube 48 is secured to the second endcap 46 by any appropriate manner known in the art, such as adhesivebonding, welding, etc.

The center tube 48 has a first end 52 adjacent to the first end cap 44and a second end 54 adjacent to the second end cap 46 of the filterelement 40. The first end 52 of the center tube 48 is provided with atleast one inlet (or first) opening 56 therethrough. Preferably, asillustrated in FIGS. 5, 6 and 9, the center tube 48 is provided withfour inlet openings 56. It will be appreciated that more or less inletopenings 56 may be employed depending upon the relative dimensions andproportions of the particular design of the filter assembly 10.Moreover, the first end 52 of the center tube 48 is provided with anactuator pin 57 that extends through the actuator opening 36 at the topend 34 of the standpipe 24 and axially depresses the closure element 28against the bias of the spring 30 to allow fuel flow through the portopenings 32 past the closure element 28 and to the fuel outlet port 20.

The first end cap 44 is provided with a central hole 45 adapted toreceive the first end 50 of the center tube 48 therethrough. An annularseal, or grommet, 58 extends across the central hole 45 in the first endcap 44 to an outer peripheral surface of the center tube 48 to seal avolume 43 inside the filter element 40 between the filter media 42 andthe center tube 48 against infiltration of contaminated fuel, asillustrated in FIG. 1. Furthermore, the first end cap 44 has asubstantially cylindrical flange portion 45 radially spaced from aninner peripheral surface 12 a of the filter housing 12.

The center tube 48 further has a standpipe opening 60 therethrough atthe second end 54 thereof adjacent to the second end cap 46 (see FIG. 8)and through which the standpipe 24 can be inserted longitudinally intothe center tube 48. An annular, resilient seal, or grommet, 62 extendsacross the opening 60 to an outer peripheral surface of the standpipe 24to seal the exit compartment 50 between the center tube 48 and thestandpipe 24 against infiltration of contaminated fuel, as illustratedin FIGS. 1 and 7. The annular seal 62 defines a central opening 64 whichaccepts the standpipe 24 in the center tube 48.

The second end cap 46 of the filter element 40 is provided with at leastone intake (or second) opening 66 therethrough radially spaced thestandpipe opening in the center tube 48. Preferably, as illustrated inFIG. 10, the second end cap 46 is provided with four intake openings 66spaced apart circumferentially around the central opening 64. It will beappreciated that more or less intake openings 66 may be employeddepending upon the relative dimensions and proportions of the particulardesign of the filter assembly 10.

As further illustrated in FIGS. 1, 7 and 8, the second end cap 46 has asubstantially cylindrical flange portion 47. The flange portion 47 ofthe second end cap 46 includes a gasket receiving groove 47 a in whichan O-ring seal 68 is positioned for sealing the second end cap 46against the inner peripheral surface 12 a of the filter housing 12. Suchan arrangement of the O-ring seal 68 separates the filter chamber 15 ofthe filter housing 12 into a contaminated, or unfiltered, fuel chamber15 a and a clean, or filtered, fuel chamber 15 b. Therefore, the secondend cap 46 of the filter element 40 sealingly engages the innerperipheral surface 12 a of the filter housing 12 through the O-ring seal68 to prevent unfiltered, contaminated fuel flow to enter the clean fuelchamber 15 b.

The cover 17 has a cover projection 72 is positioned centrally on aninterior cover top wall 74 of the cover 17 (see FIG. 2). The coverprojection 72 is adapted to be accepted into a recess 57 a formed in theactuator pin 57 of the center tube 48 and serves as support means forsupporting the actuator pin 57. While the cover projection 72 is adaptedfor adding strength to the actuator pin 57, it is of insufficient lengthto engage the closure element 28 of the flow control valve 26. The cover17 also includes a circular centering wall 76 which extends insurrounding relation to the cover projection 72. The centering wall 76is sized to be accepted into a well area 78 on the first end cap 44 (seeFIGS. 1 and 7).

In operation of the filter assembly 10 as illustrated in FIG. 1, theunfiltered (contaminated) fuel flows into the contaminated fuel chamber15 a of the filter housing 12 through the inlet port 18. The unfilteredfuel then passes through the intake openings 66 in the second end cap 46of the filter element 40 and enters the volume 43 inside the filterelement 40 between the filter media 42 and the center tube 48.Subsequently, the unfiltered fuel passes the filter media 42 of thefilter element 40 in the inside-out flow pattern into the clean fuelchamber 15 b and is cleansed of impurities. The clean fuel travels fromthe clean fuel chamber 15 b through the space between the flange portion45 of the first end cap 44 and the inner peripheral surface 12 a of thefilter housing 12 and passes through the inlet openings 56 in the centertube 48 of the filter element 40 into the exit compartment 50 betweenthe center tube 48 and the standpipe 24. The fuel then passes throughthe port openings 32 in the standpipe 24 and the flow cavities 33 of theclosure element 28 of the flow control valve 26 into the internal flowpassage 25 of the standpipe 24 and leaves the filter housing through theoutlet port 20 provided at a proximal end of the standpipe 24. Portionof the filtered fuel returns to the fuel tank (not shown) via the returnport 22.

Changing of the filter element 40 is accomplished by removing the cover17 and causing the filter element 40 to move upward by the resilientforce of the spring 30. As the end cap 46 of the filter element 40 movesupward with the cover 17, the closure element 28 of the flow controlvalve 26 also moves upward, so that its cylindrical lower portion 28 ais in blocking relation with the port openings 32. Further outwardmovement of flow element 42 is prevented by its engagement with guidering 40.

A new filter element 40 is installed in the bowl 14 by inserting thestandpipe 24 into the central opening 64 in the center tube 48. Thefilter element 40 is then moved downward. As this is done, the seal 62on the lower end cap 46 wipes away impurities from the standpipe 24 andkeeps dirty fuel away from the exit compartment 50 between the centertube 48 and the standpipe 24. Further movement of the filter element 40into the filter chamber 15 causes the actuator pin 57 of the center tube48 to enter the actuator opening 36 in the standpipe 24. The actuatorpin 57 engages and moves the closure element 28 of the flow controlvalve 26 downward to again open the port openings 32, as shown inFIG. 1. The cover 17 is then secured to the bowl 14 of the filterhousing 12. In this position, the actuator pin 57 is reinforced by thecover projection 72 providing sufficient strength to move the closureelement 28 against the biasing force of the spring 30.

The foregoing description of the preferred embodiment of the presentinvention has been presented for the purpose of illustration inaccordance with the provisions of the Patent Statutes. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. The embodiments disclosed hereinabove were chosenin order to best illustrate the principles of the present invention andits practical application to thereby enable those of ordinary skill inthe art to best utilize the invention in various embodiments and withvarious modifications as are suited to the particular use contemplated,as long as the principles described herein are followed. Thus, changescan be made in the above-described invention without departing from theintent and scope thereof. It is also intended that the scope of thepresent invention be defined by the claims appended thereto.

1. A fluid filter assembly comprising: a filter housing having a centralaxis and defining a filter chamber; a standpipe extending upwardlysubstantially coaxially to the central axis of said filter housing intosaid filter chamber; said standpipe including an internal flow passage;and a filter element removably positionable within said filter chamberof said filter housing, said filter element comprising: a tubular filtermedia circumscribing the central axis; a first end cap supporting saidfilter media at one end thereof; a second end cap longitudinally spacedfrom said first end cap and supporting said filter media at the oppositeend thereof; and a center tube extending between said second end cap andsaid first end cap, said center tube disposed about said standpipesubstantially coaxially with the central axis so as to define an exitcompartment between said center tube and said standpipe; said centertube having at least one inlet opening therethrough at a first endthereof adjacent to said first end cap for providing fluid communicationbetween said filter chamber and said exit compartment; said center tubefurther having a standpipe opening therethrough at a second end thereofadjacent to said second end cap and through which said standpipe beinginserted longitudinally into said center tube; said second end caphaving at least one intake opening therethrough radially spaced fromsaid standpipe opening in said center tube for providing fluidcommunication between said filter chamber and a volume inside saidfilter element between said filter media and said center tube.
 2. Thefluid filter assembly as defined in claim 1, wherein said filter housingincludes a cylindrical cup-shaped bowl having a closed end and anopposite open end and a cover removably attached to said open end ofsaid bowl.
 3. The fluid filter assembly as defined in claim 1, whereinsaid standpipe is provided with a flow control valve for selectivelycontrolling fluid flow through said standpipe.
 4. The fluid filterassembly as defined in claim 3, wherein said flow control valve isnormally is a closed position preventing flow through said internal flowpassage, said flow control valve is accessible from a distal end of saidstandpipe and movable into an open position allowing flow through saidinternal flow passage.
 5. The fluid filter assembly as defined in claim1, wherein said filter housing is provided with an inlet port in fluidcommunication with said filter chamber and an outlet port in fluidcommunication with said internal flow passage of said standpipe.
 6. Thefluid filter assembly as defined in claim 1, wherein said second end capof said filter element sealingly engages an inner peripheral surface ofsaid filter housing so as to separate said filter chamber of the filterhousing into a contaminated fuel chamber and a clean fuel chamber. 7.The fluid filter assembly as defined in claim 6, wherein said at leastone inlet opening in said center tube provides fluid communicationbetween said clean fuel chamber and said exit compartment, and said atleast one intake opening in said second end cap provides fluidcommunication between said contaminated fuel chamber and said volumeinside said filter element.
 8. The fluid filter assembly as defined inclaim 6, wherein said filter housing is further provided with a returnport in fluid communication with said clean fuel chamber.
 9. A componentof a filter element having filter media, comprising: a center tube,wherein the center tube is defined by a first end including at least onefluid inlet opening, and a second end including a standpipe opening, andat least one second opening that is radially spaced from said standpipeopening; and a first end cap that radially extends from and isintegrally formed with a cylindrical sidewall of the center tube,wherein the at least one second opening is formed in the first end cap,wherein the first end cap includes an axial flange portion, wherein theaxial flange portion include a radial gasket-receiving groove.
 10. Thecomponent of a filter element having filter media as defined in claim 9,further comprising: a second end cap, wherein the second end cap isremovably-secured to the cylindrical sidewall of the center tube,wherein said center tube is substantially axially aligned with a centralaxis, wherein said center tube extends between said first and second endcaps.
 11. The component of a filter element having filter media asdefined in claim 10, wherein said at least one fluid inlet opening isformed in the center tube and proximate the second end cap, wherein thecylindrical sidewall of the center tube extends through an openingdefined by the second end cap.
 12. The component of a filter elementhaving filter media as defined in claim 10, further comprising: a firstseal disposed in said radial gasket-receiving groove; a second seal thatradially seals said first end of the center tube proximate the first endcap; and a third seal that radially seals said second end of the centertube proximate the second end cap.
 13. The component of a filter elementhaving filter media as defined in claim 10, wherein said second end capincludes at least one fluid intake opening, wherein the at least onefluid intake opening is radially spaced from said standpipe opening. 14.The component of a filter element having filter media as defined inclaim 9, wherein the first end of the center tube is further defined byan axial recess for receiving a projection extending from a covermember.